| 摘要 |
PROBLEM TO BE SOLVED: To provide a dry etching process by which the occurrence of an etching stopping phenomenon and a residue can be prevented and no damage is given to a low-dielectric constant interlayer insulating film containing an SiOCH- or SiOC-based porous material and, at the same time, the area dependency with respect to a treated substrate can be reduced in dry-etching the interlayer insulating film. SOLUTION: The low-dielectric constant interlayer insulating film is etched with a mixed gas prepared by adding fluorocarbon to a main gas composed of a nitrogen gas. Since the nitrogen gas which is high in chemical reactivity, but is low in sputtering effect at etching time, as compared with argon is used, a -C-C- or Si-C- layer is formed in etching the porous low-dielectric constant interlayer insulating film containing, for example, carbon, because the carbon is removed as a -CN gas. Consequently, holes for wiring can be made finer and, at the same time, the etching rate is improved, because the occurrence of the etching stopping phenomenon and residue can be prevented. In addition, since the chemical reactivity of the nitrogen gas is low as compared with oxygen, the CHx group contained in the interlayer insulating film is not drawn out during the course of etching and the interlayer insulating film is prevented from being damaged. At the same time, the area dependency with respect to the treated substrate is small, because no reaction product is produced. COPYRIGHT: (C)2005,JPO&NCIPI
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